Selaginella Genome Adds Piece to Plant Evolutionary Puzzle 5 May 2011, by Brian Wallheimer

Selaginella genome adds piece to plant evolutionary puzzle 5 May 2011, by Brian Wallheimer

(May 5) in the journal Science. "This plant is a survivor. It has a really long history and it hasn't really changed much over time. When you burn coal, you're burning the Carboniferous relatives of these plants."

Banks said the Selaginella genome, with about 22,300 genes, is relatively small. Scientists also discovered that Selaginella is the only known plant not to have experienced a polyploidy event, in which it creates one or more extra sets of chromosomes.

Jody Banks led the effort to sequence the genome of Selaginella also is missing genes known in other Selaginella, seen through a shade screen that allows it plants to control flowering, phase changes from to be grown in greenhouses here. Selaginella is the first juvenile plants to adults and other functions. plant of its kind, a lycophyte, to have its genome sequenced. Credit: Purdue Agricultural Communication "It does these in a totally unknown way," Banks photo/Tom Campbell said.

Banks said Selaginella's genome would help scientists understand how its genes give the plant (PhysOrg.com) -- A Purdue University-led some of its unique characteristics. The genome sequencing of the Selaginella moellendorffii also will help them understand how Selaginella and (spikemoss) genome - the first for a non-seed other plants are evolutionarily connected. vascular plant - is expected to give scientists a better understanding of how plants of all kinds

evolved over the past 500 million years and could

open new doors for the identification of new pharmaceuticals.

Jody Banks, a professor of botany and plant pathology, led a team of about 100 scientists from 11 countries to sequence the genome of Selaginella, a lycophyte. Lycophytes, which are the oldest living vascular plants, shed spores to reproduce and have a single vascular vein through their leaves, as opposed to more complex vascular plants.

"There are only three families and about 1,000 species of lycophytes remaining. Selaginella has been on Earth about 200 million years," said Banks, whose findings were published Thursday

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"These metabolic genes evolved independently in Selaginella and flowering plants, so the metabolites they make are likely to be very different," Banks said. "This means Selaginella could be a huge resource for new pharmaceuticals."

Banks said the genome sequence would now be mined for more information as scientists learn more about plant evolution and applications for Selaginella's genes.

More information: The Compact Selaginella Genome Indentifies Changes in Gene Content Associated With the Evolution of Vascular Plants, by Jo Ann Banks, et al.

Abstract Vascular plants appeared ~410 million years ago then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and lycophytes (1). We report here the Photo: Selaginella moellendorffii (Jing-Ke Weng, Salk genome sequence of the lycophyte Selaginella University) moellendorffii (Selaginella), the first non-seed vascular plant genome reported. By comparing gene content in evolutionary diverse taxa, we found that the transition from a gametophyte-to- In comparing this genome sequence with others, sporophyte-dominated life cycle required far fewer researchers were able to identify genes that are new genes than the transition from a non-seed present only in vascular plants and genes present vascular to a flowering plant, while secondary only in flowering plants. These genes likely played metabolic genes expanded extensively and in important roles in the early evolution of vascular parallel in the lycophyte and angiosperm lineages. and flowering plants, respectively. Many of these Selaginella differs in post-transcriptional gene genes have unknown functions, but it is likely that regulation, including small RNA regulation of those genes that are present only in flowering repetitive elements, an absence of the tasiRNA plants may function in the development of fruits and pathway and extensive RNA editing or organellar seeds, which are important to agriculture. genes.

"For many plant genes, we have no idea what their function is," Banks said. "Knowing this gives us ideas. It's an important piece of the puzzle in Provided by Purdue University understanding how plants evolved."

Banks also noted that Selaginella and Arabidopsis thaliana, a plant widely used in research, use significantly different genes to control creation of secondary metabolites, molecules that are responsible for creating scents, seed dispersal functions, defense and other tasks. Those secondary metabolites also are used to create pharmaceuticals.

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APA citation: Selaginella genome adds piece to plant evolutionary puzzle (2011, May 5) retrieved 26 September 2021 from https://phys.org/news/2011-05-selaginella-genome-piece-evolutionary-puzzle.html

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